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(No Model.) 4 Sheets-Sheet 1. H. S. PRENTISS. CLOCK MOVEMENT AND THELIKE. No. 416,804. Patented 1m. 10, 1889.

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, 4 Sheets-Sheet 2. H. S. PRENTISS. GLOGK MOVEMENT AND THE LIKE.

No. 416,804. 'PatentedDec. 10, 1889.

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[Fm/1% ATTORNEY (No Model.) 4 Sheets-Sheet 3. H. S. PRENTIS-S.

GLOGK MOVEMENT AND THE LIKE. No. 416,804. Patented De0.'10, 1889.

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- (No Model.) 4 SheetsSheet 4.

H. S. PRENTISS.

GLOGK MOVEMENT AND THBLIKR,

No. 416,804. Patented Dec, 10, 1889.

WITNESSES INVENTUR I UNITE STATES PATENT OFFICE;

' out in the following specification and claims tion in the lane 0a Fi7.

- obtain by the use of purely mechanical means HENRY S. PRENTISS, OF NEVYORK, N. Y.

CLOCK-MOVEMENT AND THE LIKE.

SPECIFICATION forming part of Letters Patent No. 416,804, dated December10, 1889.

Application filed April 3, 1889. Serial No. 305,863. (No model.)

To all whom it may concern:

Be it known that I, HENRY-S. PRENTISS, a citizen of the United States,and a resident of New York, in the county and State of New York, haveinvented a new and useful Improvement-in Clock-Movements and the Like,of which the following is a specification.

My invention has reference to improvements in mechanical motors, andespecially to such as are adapted for use in cases where uniformity ofmotion and aconstant impulse are essentialsuch, for instance, as motorsfor operating the feed-rolls of magnesium lights or in clock-movements.

Primarily the object of my invention is to a practically uniformimpulse, especially in spring-motors, where otherwise the impulse varieswith the variation of tension in the springs. My improvement istherefore especially applicable to time-pieces, which in consequencethereof can be supplied with very powerful mainsprings and will runaccurately fora long period of time without rewinding, the effect on thependulum or other timing devices being constant regardless of thetension of the mainsprings.

With the above object'in View I combine with a motor anequalizing-spring which is connected with and continually actuates amovable member of the motor, said spring being Wound up at predeterminedintervals by the motor, all of Which is more fully pointed andillustrated in the accompanying drawings, in which- Figure 1 representsavertical section in the plane 00 00, Fig. 2, of a spring-motorembodying my invention. Fig. 2 is a vertical section thereof in theplane 3 y, Fig. 1. Fig. 3 is a section in the plane 2 .2, Fig. 2,showing the equalizing device. Figs. 4 and 5 are detail views. Fig. 6 isa section in the same plane as Fig. 1, but showing the parts indifferent relative positions. Fig. 7 is a sectional elevation showing myimprovement applied to a clock-movement Fig. 8 is a'vertical sec-Similar letters and figures indicate corresponding parts.

In the drawings, referring at present to Figs. 1, 2, and I the letter Adesignates the frame of the motor, and B is the mainspring, arranged asusual and provided with the usual means for winding. The first or greatwheel 0 of the motoris connected by a train of gear wheels with a pinionD, mounted loosely upon a post a, which is rigidly secured in the frameA.

E is a spindle or shaft arranged in line with the post a, which shaftcan turn freelyin suitable bearings, one of which may be directly in theend of the post and the other in the frame. This spindle or shaft Ishall hereinafter term the main shaft E,'and it is the member to which auniform impulse is imparted and from which power is transmitted directlyor indirectly to any mechanism or devicesuch, for instance, as tothefeed-rolls of a magnesium light or to the pendulum or regulator of atime-piece.

To the pinion D is connected so as to turn with the same an arm F,projecting radially therefrom, and provided at or near its ends withlaterally-projecting stops 1 and 2, which are arranged to hesuccessively engaged by a stop 3, located at the end of an arm G,affixed to a rock-shaft b.

H is the equalizing-spring, which at the outset is placed under adefinite tension, and which I have shown in the form of a spiral spring,having its inner end attached to the main shaft E and its outer endsecured to a post on the winding arm F. On the main shaft is aneccentric 4, which engages with a bifurcated arm I, projecting from therock-shaft b, the vibrations of said arm, due to the rotation of themain shaft, being transmitted to the stop-bearing arm G.

Referring to Figs. 1 and 2, the stop 1 on the winding-arm F is engagedby the stop 3 of arm G, and consequently is prevented from turning inthe direction of arrow 10, in which direction the force of themainspringB would normally impel it. In the meantime theequalizing-spring, being under tension, turns the main shaft in thedirection of arrow 10. W'hen the eccentric 4 draws the arm I downward,or in the direction of arrowll, Fig. 1, the stop 1 is released from stop3, and the mainspring is free to act. The winding-arm F, under theimpulse of the mainspring, is rotated in the direction of arrow 10 untilthe stop 2 is engaged by the stop 3, (see 'Fig. 4,) which, as hereshown, is one-half a rotation, and the e u1alizing-spring is wound up tocorrespond. \Vhen the main shaft has turned sufficiently to cause theeccentric 4 to raise the arm, the stop 2 is released from step 3 and thewinding-arm completes the revolution. ()n inspection of Figs. 1 and 3 itwill be noticed that stop 1 is farther removed from the center of thearm F than stop 2, so'that when the arm G is in its highest position theupper edge of stop 8 will engage withthe lower edge of stop 1, and whenin its lowest position the lower edge of stop 3 will engage the upperedge of stop 2.

The equalizing-spring ll is best made in the form of a spiral spring,and in practice I make use of a very long light spring, which at theoutset is placed under a definite tension. This tension is sustained bythe periodical rewinding to which the spring is subjected.

Instead of winding the spring" periodically through half a turn, asillustrated, the winding-arm and the stops could be arranged to coil thespringperiodieally through one-quarter of a turn or less; but.- I havefound that when a long hair-spring is used no appreciable increase oftension follows the winding of the spring through a half-turn. It willbe noticed that the main shaft E rotates in the same direction as thespring is wound, and that it turns through half a revolution before therewindin g of the spring takes place. Consequently the impulse on theshaft is constant at all times.

From the foregoing description it will be readily understood that thegeneral function of the equalizing-spring is to transmit c011- stantlyto the main shaft a definite impulse regardless of the existing tensionof the mainspring or other source of power, the said equalizing-springbeing always wound to a definite extent and always under the sametension.

The form of motor just described is especially adapted for magnesiumlights, where a constant impulse is required for continuously feedingthe ribbon along, the velocity with which the rolls are turned beingdetermined by any suitable timing device. One form of timing deviceIhaveillustratedin Figs. 7 and 8 of the drawingsviz.,. an escapementandpendulum, as ordinarily used in clocks-and I will now describe thearrangement of my improvement in time-pieces.

I will not at present enter into the construction of the clock-movementhere shown, as my equalizing device can be applied to any well-knownmovement.

In Figs. '7 and 8, Eis the arborof the scapewheel J, which arborcorresponds to the main shaft of Figs. 1 and 2. The inner end of theequalizing-spring H is secured to said arbor as before, and the pinionD, carrying the arm F, is connected with the train of wheelsconstituting the clock-movement, and conse quently is ultimately inconnection with the center wheel K on the center arbor N. Thescape-wheel J is engaged by an anchor L, connccted with a pendulum M, asusual. The action of the motor is the same as before. \Vhile the stop 23engages either of the stops 1 2 the train of wheels is held out ofaction; but on release of either stop 1 or stop 2 it is free to move andto actuate the hands m and 71/ of the clock. As here shown, theclockmovement is released. at. every halfrevolution of the scape-wheelJ, which is so geared that the hands are moved twice each minute througha space corresponding to one-half a minute on the dial at each releaseof the motor. In the'case of clocks embodying a weightmovement theequalizing-spring counteracts any irregularities in the construction ofthe gears constitutii'lg the movement and any variation in the frictionthereof. The use of such powerful mainsprings as my invention willpermit of would ordinarily involve the use of a crank-arm or its equh'alen't for winding the said springs. This I propose to avoid by placingthe winding arbor or arbors outside of the spring or springs.

In the example shown in Figs. 7 and 8 of the drawings I employ a commonwindingarbor O for both mainsprings 13' B, which is connected by trainsof gears e (Z c with the first or great wheels 0 C and by a third trainf g with the center arbor, said trains at the same time forming also aportion of the clock train, and the trains c d reducing the powerrequired at the winding-arbor. The pinion c of train 0 (Z c is made fastto the windingarbor 0, while the gear-wheel fof train f g is loosethereon and carries a detent i, engaging a ratchet-wheelj, fast on thearbor 0, so that in winding up the springs this wheel fwill not rotate.The winding-arbor may be similarly placed and connected when only onemainspring B is used in the clock-movement, and it is evident that threeor more mainsprings could be geared together in the same manner.

\Vhat I claim as new, and desire to secure by Letters Patent, is-

1. In a clockmovement, an equalizingspring for the governing member anda mainspring for actuating the train, normally held out of action andreleased at determinate intervals to rewind the equalizing-spring and toactuate the movement, substantially as described.

2. In a clock-movement, a mainspring for aetuatin g the train, normallyheld out of action, an equalizing-spring for the governing member,adapted to be coiled by said mainspring, and a device actuated by theuncoiling of the equalizing-spring to release the mainspring, saidmainspring on its release recoiling the equalizing-spring and actuatingthe train, substantially as described.

3. In a clock-movement, a stop for holding the mainspring out of action,an equalizingspring for the governing member incorpo- IIO rated in saidmovement, and a device for releasing the mainspring to coil theequalizingspring and to actuate the train, substantially as described.

4. In a clock-movement, a timing device, an equalizing-spring for thetiming device controlled thereby, a mainspring for recoiling theequalizing-spring at determinate intervals and for actuating the trainduring such periods of recoiling, a stop for the mainspring, and adevice actuated through the uncoiling of the equalizing-spring torelease the mainspring from the action of the stop, substantially asdescribed.

5. In a clock-movement, a mainspring for actuating the train, normallyheld out of action, an equalizing-spring for the governing member,adapted to be coiled by said mainspring through the intermediate train,and a device actuated by the uncoiling of the equalizing-spring torelease the mainspring, said mainspring, when released, recoiling theequalizing-spring and actuating the movement during such period ofrecoilin g, substantially as described.

6. In a clock movement, an equalizing mechanism incorporated in thetrain or handactuating mechanism and controlling the mainspring, saidmainspring recoiling the spring of the eqalizing mechanism and actuatingthe said train during the period of recoiling the said spring,substantially as described.

7. The combination of a mainspring, an equalizing-spring, a winding-armarranged to be actuated through an intermediate train by the mainspringto coil the equalizing-spring, and suitable stopping and releasingdevices, substantially as described.

8. The combination of a mainspring, an equalizing-spring, a winding-armarranged to be actuated through an intermediate train by the mainspringto coil the equalizing-spring, an escapement for controlling theuncoiling of the equalizing-spring, and suitable stopping and releasingdevices, substantially as described.

9. The combination of amainspring, a revoluble shaft, a train ofgear-wheels between the shaft and the mainspring, all constituting amotor, a winding device carried by one of the gear-wheels of the train,an equalizingspring having one end attached to the shaft and the otherto the winding device, a regulator or governing member, a stop forholding the mainspring out of action, and a releasing device actuated atdeterminate intervals, substantially as described.

10. Ina mechanical motor, the combination of the mainspring,a mainshaft, a windingarm, a spring having its inner end attached to the mainshaft and its outer end to the winding-arm, a tripping mechanismactuated by the main shaft, and a gear-connection between the mainspringand the winding-arm, substantially as described.

11. The combination, with the mainspring and the main shaft, ofawinding-arm having two stops, a spring attached to the main shaft andto the Winding-arm, a stop for successively engaging the stops on thewindingarm, a cam or eccentric on, the main shaft for actuating thelatter stop, and a connection between the mainspring and the winding-armfor actuating the latter when released from the stop, substantially asdescribed.

12. An equalizing mechanism for springmotors, consisting of a revolubleshaft, a winding-arm arranged to turn about a center in line with theshaft and provided with two stops, an equalizing-spring having one endattached to the revoluble shaft and one to the winding-arm, an armprovided with a stop adapted to engage with the stops of thewinding-arm, a cam on the revoluble shaft, and an arm engaged by thesaid cam and connected with the stop-bearing arm, substantially asdescribed.

13. In a mechanical motor, the combination of a mainspring, awinding-arbor, and gears connecting the windingarbor with thespringgear, said gears forming a part of the train of the motor,substantially as described.

14. In a mechanical motor, the combination of two or more mainsprings, acommon winding-arbor, gears connecting the winding-arbor to thespring-gears, and a train of gears connecting the winding-arbor tothecenter arbor, said gears forming a part of thetrain of the motor,substantially as described.

15. In an equalizing mechanism for springmotors, a revoluble shaft, anescapementwheel mounted on said shaft, a winding device, a spring havingone endattached to the shaft and the other to the winding device, and agear connected with the motor and actuating the winding device, all saidparts being arranged about one and the same center line or axis,substantially as described.

16. The combination, with the frame A, of a post a, secured in saidframe, a shaft E, arranged in line with the post and having a bearingtherein, a winding device F, mounted on the post, a spring H, connectedwith the shaft and the winding device, a stop, and a cam at, engagingsaid stop, substantially as described.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two witnesses, this 29th day of March, 1889.

HENRY S. PRENTISS Witnesses: EDW. S. GALINGER, EDWIN F. STERN.

